Luminescence properties of Ca2Si5N8:Eu2+ prepared by gas-pressed sintering using BaF2 as flux and cation substitution

Eu2+ doped Ca2Si5N8 phosphors were successfully prepared by gas-pressed sintering. The red-shift of the emission band from 608 nm to the longer wavelength 622 nm of the Ca2Si5N8:Eu2+ phosphor under blue excitation has been achieved, and a large enhancement in the emission intensity has been obtained by using BaF2. XRD data revealed that the lattice of Ca2Si5N8:Eu2+ was expanded with Ba2+ ion doping. XPS results suggested that there were more Eu2+ ions incorporated into the lattice of Ba2+ doped samples than those of the undoped samples. The doping effect of Ba2+ ions has been discussed in detail.